Differential inhibition of cytosolic and membrane‐derived protein kinase C activity by staurosporine and other kinase inhibitors

Budworth, Joanna; Gescher, Andreas J.

doi:10.1016/0014-5793(95)00227-z

Cited by 43 publications

(21 citation statements)

References 20 publications

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“…While this is a novel finding in regard to cardiac Lcl, Bourinet et al (1992) that both Cl-and delayed-rectifier K+ channels in these myocytes are regulated by one or more Ca2+ -dependent rather than Ca2+-independent PKC isoforms. In this regard, we note recent studies suggesting that H-7, the kinase inhibitor used in our tests, preferentially inhibits Ca2+-dependent (Ison et al, 1993), membrane-bound (Budworth & Gescher, 1995) PKC. Relation between PMA-induced 1c, and PKA-activated 'cl There is considerably more information available on the activation of cardiac Cl-channels by PKA than by PKC (Gadsby et al, 1995). Hume and colleagues (Levesque et al, 1993;Hume & Horowitz, 1995) have identified the cardiac Clchannel activated by PKA as an alternatively spliced variant of the cystic fibrosis transmembrane conductance regulating protein (CFTR) that is commonly found in epithelial cell membranes (e.g.…”

Section: Indications Of Ca2"-dependent Pkc Involvementsupporting

confidence: 55%

Phorbol ester activation of chloride current in guinea‐pig ventricular myocytes

Shuba

Asai

McDonald

1996

British J Pharmacology

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1 Although earlier studies with phorbol esters indicate that protein kinase C (PKC) may be an important regulator of Cl-current (Icl) in cardiac cells, there is a need for additional quantitative data and investigation of conflicting findings. Our objectives were to measure the magnitude, time course, and concentration-dependence of Ic, activated in guinea-pig ventricular myocytes by phorbol 12-myristate 13-acetate (PMA), evaluate its PKC dependence, and examine its modification by external and internal ions. 2 The whole-cell patch clamp technique was used to apply short depolarizing and hyperpolarizing pulses to myocytes superfused with Na+-, K+-, Ca2+-free solution (36°C) and dialysed with Cs' solution. Stimulation of membrane currents by PMA (threshold < I M, EC50s 14 nM, maximal 40% increase with > 100 nM) plateaued within 6 -10 min. 3 PMA-activated current was time-independent, and suppressed by 1 mM 9-anthracenecarboxylic acid (9-AC). Its reversal potential (Erev) was sensitive to changes in the Cl-gradient, and outward rectification of the current-voltage (I-J) relationship was more pronounced with 30 mM than 140 mM Cl-dialysate. 4 The relative permeability of PMA-activated channels estimated from Frev measurements was I-> Cl > > aspartate. Channel activation was independent of external Na+.5 PMA failed to activate Ic, in myocytes pretreated with 1-(5-isoquinolinesulphonyl)-2-methylpiperazine (H-7) or dialysed with pCa 10.5 solution. Lack of response to 4cc-phorbol 12, 13-didecanoate (aPDD) was a further indication of mediation by PKC. 6 I1c induced by 2 giM forskolin was far larger than that induced by PMA, suggesting that endogenous protein kinase A is a much stronger Cl-channel activator than endogenous PKC in these myocytes. 7 The macroscopic properties of PMA-induced I1c appear to be indistinguishable from those of PKAactivated Ics. We discount stimulation of PKA by PMA as an explanation, and conclude that endogenous PKC may activate PKA-regulated Cl-channels in these myocytes.

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Section: Indications Of Ca2"-dependent Pkc Involvementsupporting

confidence: 55%

Phorbol ester activation of chloride current in guinea‐pig ventricular myocytes

Shuba

Asai

McDonald

1996

British J Pharmacology

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“…Of interest PKC-( of elderly subjects apparently dissociated from the particulate fraction and moved to the cytosol. PKC-( has been already demonstrated in the membrane of other cell types in the resting state [32] and that raises the possibility that this 'reverse translocation' may occur in other cells. We can not offer a conclusive explanation at this time.…”

Section: Discussionmentioning

confidence: 91%

Cellular distribution of protein kinase C isozymes in CD3‐mediated stimulation of human T lymphocytes with aging

et al. 1995

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Protein kinase C (PKC) is involved in a variety of cellular responses, such as the expression and secretion of IL-2, the regulation of cytotoxic killing and cell proliferation. It is known that these immune functions are altered with aging. Here, we show that anti-CD3-triggered T cell proliferation is significantly decreased with aging and that H7, an inhibitor of PKC, impairs the anti-CD3-induced T cell proliferation in a differential manner, lymphocytes of healthy young subjects being more sensitive to the PKC inhibitor than those of elderly subjects. We examined (Western blot) the presence and the cellular distribution of PKC isozymes in T lymphocytes of healthy young and elderly subjects in the resting state and after anti-CD3 mAb stimulation using antibodies directed against PKC 6,/3, 8, e and isoforms in the cytosol and the plasma membrane fractions. These five PKC isotypes were present in human T cells of young and elderly subjects. However, their distribution between the cytosolic and membrane fractions varied according to the isozymes and the age of the subjects. In resting lymphocytes of young subjects, all the PKC isozymes were found in the cytosolic fraction, except PKC-~. In resting lymphocytes of elderly subjects PKC-~ and -e were almost equally distributed between the cytosolic and the membrane fractions, whereas PKC-, and -~ were mainly found in the membrane fraction and PKC-/3 was almost exclusively located in the cytosolic fraction. The translocation of PKC-c~, -/3, -~ and -E could be observed under anti-CD3 mAb stimulation in lymphocytes of young subjects, while in the case of elderly subjects only the PKC ]3 isoform was translocated. Our results suggest that the decreased availability of cytosolic PKC may contribute to the diminished PKC-dependent responses to CD3-triggered stimulation of human T lymphocytes with aging.

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“…Other studies have addressed the selectivity of staurosporine and its analogs to inhibit soluble PKC and membrane-associated PKC. Ro-31-8220, in particular, showed a striking selectivity for membrane-associated PKC, while GF109203X inhibited the soluble and membrane-associated forms of PKC to the same extent (35,36). Although all of these studies suggest that GF109203X is less selective for particular PKC isozymes than Ro-31-8220, the molecular reasons for these observations remain speculative.…”

Section: Discussionmentioning

confidence: 99%

The Selective Protein Kinase C Inhibitor, Ro-31-8220, Inhibits Mitogen-activated Protein Kinase Phosphatase-1 (MKP-1) Expression, Induces c-Jun Expression, and Activates Jun N-terminal Kinase

Beltman¹,

McCormick²,

Cook³

1996

Journal of Biological Chemistry

180

145

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The role of protein kinase C (PKC) in inflammation, mitogenesis, and differentiation has been deduced in part through the use of a variety of PKC inhibitors. Two widely used inhibitors are the structurally related compounds GF109203X and Ro-31-8220, both of which potently inhibit PKC activity and are believed to be highly selective. While using GF109203X and Ro-31-8220 to address the role of PKC in immediate early gene expression, we observed striking differential effects by each of these two compounds. Growth factors induce the expression of the immediate early gene products MAP kinase phosphatase-1 (MKP-1), c-Fos and c-Jun. Ro-31-8220 inhibits growth factor-stimulated expression of MKP-1 and c-Fos but strongly stimulated c-Jun expression, even in the absence of growth factors. GF109203X displays none of these properties.These data suggest that Ro-31-8220 may have other pharmacological actions in addition to PKC inhibition. Indeed, Ro-31-8220 strongly stimulates the stress-activated protein kinase, JNK1. Furthermore, Ro-31-8220 apparently activates JNK in a PKC-independent manner. Neither the down-regulation of PKC by phorbol esters nor the inhibition of PKC by GF109203X affected the ability of Ro-31-8220 to activate JNK1. These data suggest that, in addition to potently inhibiting PKC, Ro-31-8220 exhibits novel pharmacological properties which are independent of its ability to inhibit PKC. Protein kinase C (PKC)1 is a large and diverse family of protein kinases, whose members are differentially regulated by calcium, phorbol esters, diglycerides, and phosphatidic acid (for a review, see Ref. 1). The various PKC isozymes play important signaling roles in cellular growth, differentiation, and homeostasis. The reported cellular roles of PKC have been identified largely through the use of PKC activators and inhibitors. The bisindolemaleimide class of compounds are staurosporine analogs which by all reports are specific for PKC (2, 3). Two widely used bisindolemaleimides, GF109203X and Ro-31-8220, differ by a single functional group, and although their isozyme specificity varies slightly, they are both potent and selective PKC inhibitors.In addition to cellular responses that may be attributed directly to PKC, PKC signaling pathways likely also contribute to cellular signaling through cross-talk mechanisms with other signaling cascades. Multiple lines of evidence indicate a role for PKC in regulating the ERK and JNK cascades which regulate transcription factors in response to external stimuli. The ERK cascade, a growth factor-stimulated signaling cascade is regulated by the Ras and Raf protooncogenes which activate MEK which in turn activates ERK1 and ERK2 (4, 5). ERK1 and -2 accumulate in the nucleus and phosphorylate and transactivate the transcription factor TCF/Elk-1 (6). A parallel signaling pathway activated by cellular stresses such as uv light and translational inhibitors leads to the activation of MEKK1, SEK, and in turn JNK1 and JNK2 (7, 8). The major role of the JNK signaling pathway is believed to be the...

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Differential inhibition of cytosolic and membrane‐derived protein kinase C activity by staurosporine and other kinase inhibitors

Cited by 43 publications

References 20 publications

Phorbol ester activation of chloride current in guinea‐pig ventricular myocytes

Phorbol ester activation of chloride current in guinea‐pig ventricular myocytes

Cellular distribution of protein kinase C isozymes in CD3‐mediated stimulation of human T lymphocytes with aging

The Selective Protein Kinase C Inhibitor, Ro-31-8220, Inhibits Mitogen-activated Protein Kinase Phosphatase-1 (MKP-1) Expression, Induces c-Jun Expression, and Activates Jun N-terminal Kinase

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